chore(package): update sinon to version 2.0.0

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -61,7 +61,7 @@
     "proxyquire": "^1.7.10",
     "regexp.escape": "^1.0.2",
     "rimraf": "^2.2.0",
-    "sinon": "^1.17.7"
+    "sinon": "^2.0.0"
   },
   "engines": {
     "node": ">=0.12",